One conventional approach to dispensing a product onto a target application surface is via atomisation of that product. One way of achieving atomisation is to combine the product with a propellant (compressed gas) in a pressurized unit having a dispensing valve fluidly connected to a dispensing outlet. On opening the dispensing valve, the product is forced therethrough and dispensed via the outlet in an atomized form onto the target application surface.
The present inventors have established, however, that current atomization technology generally does not deliver a satisfactory product distribution onto the target area. In particular, the distribution is observed to be uneven, with, for example, increased deposition occurring in the centre and correspondingly reduced deposition towards the extremities of the target site. In addition to the uneven spread of active agent and resulting uneven achievement of benefit across the target site, increased deposition in one area, for example the centre, may additionally result in the formation of unsightly residues and unpleasant cooling in that region of the consumer's skin, due to the increased amounts of product deposited there and increased amounts propellant evaporating at that location.
In addition to the above-mentioned shortcomings, a single outlet spray head also places physical limitations on the composition which may be sprayed. In particular, high viscosity compositions may not be practically sprayed, because insufficient energy may be retained in such a fluid under typical pressurisation conditions for it to become sufficiently atomised on leaving the spray outlet.
With reference to U.S. Pat. No. 3,767,125, a multi-outlet spray head is proposed for spraying dry powder aerosols.
With reference to U.S. Pat. No. 5,516,045, an alternative multi-outlet spray head is disclosed, especially for spraying hair lacquer.
It would be advantageous to provide a spray head which overcomes the disadvantages of spray heads disclosed in the prior art.